Processing machine with lockdown rotor

ABSTRACT

In a machine for processing semiconductor wafers, a rotor includes two pairs of combs. A lock down mechanism has a lock bar, temporarily engaged and moved by a loading/unloading robot, drives a retainer against the edges of the wafers, to better hold them in place during processing. Contamination via generation of particles is reduced. Combs on the rotor have a resilient strip. The lower edges of the wafers compress slightly into or deflect the resilient strip, when urged into place by the lock down mechanism.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to centrifugal processingsystems with rotors adapted to hold semiconductor articles, such aswafers or other semiconductor microelectronic articles.

2. Background

During the fabrication of flat media, such as microelectronic andsemiconductor articles, various manufacturing steps involve theapplication of processing liquids and gases to the articles beingprocessed. The application and removal of these processing fluids to andfrom the exposed surfaces of the workpieces or articles is enhanced byspinning movement of the articles within the processing chamber.Centrifugal action helps to apply fluids on the surfaces beingprocessed.

As one example, after a flat media article has been cleaned, it must bedried. Any water droplets or other cleaning fluid that remain have atleast some potential of leaving a residue or particles which mayinterfere with subsequent operations or cause defects in the resultingelectronic products. As with most manufacturing operations relating tosemiconductors and microelectronic devices, having an exceptionallyclean environment, substantially free of particles, residues, etc., is acritical factor. Spinning the articles helps remove water or otherprocessing liquids, so that such residues or particles are less likelyto remain. Spinning also reduces processing time as droplets arephysically removed via centrifugal force.

In the centrifugal processing machine described in the U.S. Pat. No.5,784,797, incorporated by reference, the articles are held in a rotorthat includes a rotor frame for holding the articles in an array,without an article carrier. The rotor has retainers which contact thearticles to hold them in place. While this type of design may have metwith varying degrees of success, several disadvantages remain.Specifically, contaminant particles may be created by the interaction ofthe edges of the articles, and the rotor surfaces supporting them.

Post-process analyses of the articles (semiconductor wafers), processedin a machine as described above, show residue signatures of carbon andfluorine, and in some cases chlorine. The residues were also present onthe device side of the wafers, with the highest defect density near theedges of the wafers. This residue generation is caused by the relativeclocking motion between the wafers and the rotor. This motion produceskinetic friction at the contact interfaces, causing the wafer edges toabrade, and wear on the thermoplastic rotor combs.

Therefore, there is a need for an improved machine to reduce oreliminate the creation, deposition and redistribution of residues andparticles.

SUMMARY OF THE INVENTION

In a first aspect of the invention, a contact bar of a lockdownmechanism approaches the articles or wafers in a rotor with a trajectorythat is largely normal to the edge of the wafers. This reduces oreliminates sliding contact at the edges of the articles and hencereduces particle generation.

In another, separate aspect of the present invention, improved combsinclude a plurality of projections and a rod or strip made from aresilient material. While the teeth of the combs guide and hold thearticles, the resilient rod allows the articles to be better securedinto the rotor, with less risk of damage.

Accordingly, it is an object of the invention to provide an improvedrotor for use in processing semiconductor articles.

This and further objects and advantages will be apparent to thoseskilled in the art in connection with the drawings and the detaileddescription of the preferred embodiment set forth below.

BRIEF DESCRIPTION OF THE DRAWINGS

One or more preferred forms in the invention are described herein withreference to the accompanying drawings.

FIG. 1 is a perspective view of the present semiconductor articleprocessing machine.

FIG. 2 is a perspective view of a transfer implement or hand used in themachine of FIG. 1.

FIG. 3 is a perspective view of the centrifugal processor rotor withinthe process chambers shown in FIG. 1.

FIG. 4 is the front view of the rotor shown on FIG. 3.

FIG. 5 is a perspective view of the base combs shown in FIGS. 3 and 4.

FIG. 6 is a cross-section view thereof.

FIG. 7 is a front view thereof.

FIG. 8 is an enlarged view of a section of the comb portion shown inFIG. 5.

FIG. 9 is a perspective view of the lateral or side combs, shown in FIG.4.

FIG. 10 is a cross-section view thereof.

FIG. 11 is a front view thereof.

FIG. 12 is an enlarged view of a section of the comb shown in FIG. 9.

FIG. 13 is a perspective view of the right side article retainer shownin FIGS. 3 and 4, with the left side article retainer shown thereinbeing a mirror image of the right side article retainer.

FIG. 14 is a perspective view of the retaining bar cover, which is shownattached to the article retainer in FIG. 13.

FIG. 15 is a perspective view of one of the arms on the article retainershown on FIG. 13.

FIG. 16 is a front view thereof.

FIG. 17 is an enlarged view of a section of the rotor shown in FIG. 3.

FIG. 18 is a partial perspective view of one of the lock bars shown inFIGS. 3 and 17.

FIG. 19 is a schematic cross-section view of the rotor shown in FIG. 3,showing the left side article retainer in an up or open position.

FIG. 20 is a schematic cross-section view of the centrifugal processorrotor shown in FIG. 3 showing the left side article retainer moved intoan intermediate position by the lock bar shown in FIGS. 3 and 17.

FIG. 21 is a schematic cross-section view of the centrifugal processorrotor shown in FIG. 3, showing the left side article retainer moved intoa down or closed position, by the lock bar shown in FIGS. 3, 17 and 18.

FIG. 22 is a perspective view of the centrifugal processor rotor shownin FIG. 3 holding a batch of round articles.

FIG. 23 is a side view thereof.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Turning now in detail to the drawings, as shown in FIG. 1, a machine 30for processing flat media (i.e., semiconductor wafers, flat paneldisplays, data disks, photo masks, and other semiconductor ormicroelectronic articles, referred to herein collectively as “wafers”)has an enclosure 32 containing a first section 35 for temporarilystoring wafers, and a second section 37, for processing wafers. Thefirst section 35 includes a load/unload unit 34, for moving wafers intoand out of the enclosure 32. The first section 35 also preferablyincludes shelves or other storage areas 36, for temporarily storing thearticles 44 to be processed.

The second or processing section 37 includes one or more processchambers 38. A rotor 60 is contained within each of the process chambers38, for rotating the wafers 44 within the chambers 38.

A transport device or robot 40 is moveable between the first or storagesection 35 and the processing section 37, to move wafers to be processedfrom the storage locations 36, into the process chambers 38, and toremove processed wafers from the chambers 38 back to the storagelocations 36, to cycle the wafers through the machine 30, as described,for example, in U.S. Pat. Nos. 5,544,421; 5,660,517; 5,678,320; and5,784,797, incorporated herein by reference.

Turning to FIGS. 1 and 2, the robot or transfer device 40 has a hand orend effector 42 including a frame 50. A pair of arms 52 having groovesor slots 56 are attached to the front side of the frame 50. Driveopenings 54 extend through the top corners of the frame 50. The driveopenings 54 are symmetrical or mirror images of each other, as describedin U.S. Pat. No. 5,784,797.

Referring now to FIGS. 1 and 3, the rotor 60 within the process chamber38 includes a front ring 62 and a back plate or ring 64 connected toeach other by connecting bars 68. A drive shaft 80 joined to the backplate 64 is linked to a spin motor 81 behind the process chamber 38, forspinning the rotor during processing. The connecting bars 68 extendparallel to the drive shaft 80, and perpendicular to the plane of thefront ring 62 and the back plate 64. The rotor 60 includes a pair ofbase combs 90, and a pair of side combs 110 opposite to a lockdownassembly 70, for securing the wafers 44 in place during processing.

Referring now to FIG. 4, which shows the rotor 60 in its upright or 0°position, the base combs 90 are located at approximately the 5:00o'clock and 7:00 o'clock positions, while the side combs 110 are locatedapproximately at the 4:00 o'clock and 8:00 o'clock positions. Thelockdown assembly 70 is centered about the 12:00 o'clock position, andthe vertical center line of the rotor 60.

Turning now to FIGS. 5-8, the base comb 90 has a plurality of teeth 92spaced apart by gaps 98. The teeth 92 are formed generally in the shapeof a four-sided pyramid. Each tooth 92 has a flat back surface 91, aflat front surface 93, and flat side surfaces 95 and 97. The surfaces91, 93, 95 and 97 taper or converge upwardly towards a rectangularplateau 96 at the tip or top end of each tooth 92. The gap 98 betweenadjacent teeth 92 has flat side walls 99 and a flat bottom 101. Thepitch or spacing between the teeth 92 matches the pitch of the groovesor slots 56 on the hand 42.

Side hooks 102 are attached to the lower front surface 93 of each of theteeth 92. Each side hook 102 has a dove tail O-ring slot 104. An O-ringstrip or rod 106, comprising a resilient material, is held within thedove tail O-ring slot 104 in the side hooks 102. The O-ring strip ispreferably Kalrez 1050LF perfluoro elastomer. The combs 90 and 110 arepreferably a harder thermoplastic. The O-ring strip 106 extendsalongside the teeth 92, substantially for the entire length of the basecomb 90. The lower end of the base comb 90 includes a dove tail mountingslot 108, for attaching the base comb 90 onto the connecting bars 68, asshown in FIG. 3.

Specifically, the top or inner ends of the connecting bars 68 have amale dove tail fitting as shown in FIG. 4. One or more base combs 90 areattached onto the connecting bars 68, by sliding them on from one end,and pinning them in place. In the embodiment shown in FIG. 3, twoseparate base combs 90 are provided on the connecting bars 68 at the5:00 o'clock and 7:00 o'clock positions. However, the specific lengthand/or number of base combs 90 used will vary with the length (and wafercapacity) of the rotor 60. A pin 109 extending through the base comb 90and connecting bar 68, secures the base comb into a fixed and presetlongitudinal (front/back) position. This prevents movement of the basecomb 90 after it is installed, and maintains alignment between the teethof the two base combs 90, as well as the teeth in the side combs 110.

Turning now to FIGS. 9-12, the side combs 110 are similar to the basecombs 90, except that the side combs are positioned at approximately the4:00 o'clock and 8:00 o'clock positions. In addition, the teeth 112 ofthe side combs 110 have rounded sides 114 and 115, an elongated flatback surface 120, and a shorter more vertical flat front surface 118.The rounded side walls 114 and 115 and flat front and rear surfaces 118and 120 come together at a small rectangular plateau or peak 116. Theremaining features of the side combs, as shown in FIGS. 9-12, are thesame as the features described above in connection with FIGS. 5-8.

Referring momentarily to FIGS. 3 and 17, the lockdown assembly 70includes a pair of lock bars and retainers, which are pivotally attachedto the front ring 62 and back plate 64. The lock bars move against theretainers, in a cam-like way, to lock the wafers 44 securely in placewithin the rotor 60, for processing. As shown in FIG. 3, the retainers130 and 160, and lock bars 170 and 188, are attached to and extendbetween the front ring 62 and back plate 64, in a direction parallel tothe connecting bars 68 and drive shaft 80. Although the drawings show anembodiment having both left and right retainers 130 and 160, and leftand right lock bars 170 and 188, principles of the invention applyequally as well to an embodiment having a single retainer and lock baror having more than two of each.

Referring to FIG. 13, the left retainer 130 has a pivot bar 132 which ispivotably attached to the front ring 62 and back plate 64 via bushings134. One or more cam arms 136 (3 in the design shown) have a back wall152 attached to the pivot bar 132, and a front notch 154 attached to acontact bar 138, as shown in FIGS. 13, 15, and 16. The contact bar 138,which is the surface which actually contacts the peripheral edges of thewafers, to secure them in place, is covered with a resilient elastomernon-reactive cover 140, held into place on the contact bar 138 viaplastic pins 142 or similar fasteners. The cover 140 is also preferablyKalrez 1050LF.

The use of an elastomer material for the cover 140 and O-ring strip 106increases the contact and support of the edges of the wafer, despitevariability in the rotor and wafer diameters, due to tolerances. As thewafers are better and more reliably supported, clocking or inadvertentwafer movement during processing, and the associated generation ofcontaminant particles, is reduced.

Turning specifically to FIGS. 15 and 16, the cam arm 136 has a straightouter section 146 transitioning into a first curved section 148, whichin turn transitions into a second curved section 150. The surfaces 146,148 and 150 form a cam surface which controls pivoting movement of theretainer 130, when it is driven or acted on by the lock bar, as furtherdescribed below.

FIG. 13 shows the left retainer 130, which pivots about an axis just tothe left side of the 12:00 o'clock position or vertical axis of therotor 60, as shown in FIG. 4. The right retainer 160 as shown in FIGS.3, 4 and 17, is preferably a mirror image of the left retainer 130, andhas a pivot access just to the right of the 12:00 o'clock position orvertical axis of the rotor 60.

Turning to FIG. 18, the left lock bar 170 has a cam bar 172 having anouter or lower edge 182. A drive stem 178 extends outwardly from a stemarm 176 attached to the cam bar 172. A stem cap or cover 180 is securedonto the drive stem 178. Referring also to FIGS. 3, and 17, the lock bar170 is pivotably attached to the front ring 62 and back plate 64 viabushings 174. The edge 182 of the cam bar 172, which slidably engagesthe top cam surface of the cam arms 136 of the retainer 130, alsopreferably is covered with a non-metal material, to reduce or avoidgenerating particles during contact with the cam arms.

The right lock bar 188 may be a mirror image of, or the same as, theleft lock bar 170.

Referring to FIG. 4, which shows the rotor 60 in the locked or closedposition, a retainer spring 190 on the back plate 64 engages bothretainers 130 and 160, and biases or urges them outwardly or upwardly(in opposition directions, away from the rotor center) so that thecontact bar 138 of each retainer is moved outwardly, or away from thecentral spin axis of the rotor 60. A left lock bar spring 192 has aninner end 193 pivotably attached to the back plate 64, coils 195, and anouter end 197 pivotably attached to the left lock bar 170. The coils 195urge the inner end 193 and the outer end 197 apart. When the rotor 60 isin the open position, for loading or unloading, as shown in FIG. 19, thespring 192, which pivots with the lock bar 170 about the inner end 193,pushes the lock bar counterclockwise, to hold it up or open. The counterweight 196 provides added holding force, when the rotor is spinning, viacentrifugal force acting to pivot the lock bars into the closedposition. A cut out 201 in the counterweight 166 contacts a hardstop 211on the back plate 64, to limit travel of the lock bars.

The right lock bar spring 194 similarly has an inner end 203, coils 205,and an outer end 207, providing operation which is a mirror image of theleft side. The springs 192 and 194 tend to hold the lock bars up, whenthe rotor 60 is in the open position, and tend to hold the lock barsdown or closed, when the rotor 60 is in the closed or locked position.

In FIG. 19, the lockdown assembly 70 (shown and described here only withrespect to the left side) is shown in the up or open position, to allowinsertion or removal of wafers 44. Due to the geometry (lever armlengths) of the lock bar 170 and retainer 130, and due to the springconstants of the springs 190 and 192, the lockdown assembly 70 stays inthe open position shown in FIG. 19, as the turning moment exerted by theleft lock bar 170, via the spring 192, is not sufficient to move theretainer 130 against the force of the retainer spring 190. Consequently,the lockdown assembly 70 stays in the up, retracted or disengagedposition, allowing the wafers to be freely inserted.

As the hand 42, shown in FIG. 2 on the robot 40, shown in FIG. 1, movesinto the process chamber 38, with a batch of wafers 44 to be processed,the lower section 57 of the drive opening 54 moves over the drive stem178. With the hand 42 properly positioned, i.e., so that the wafers 44are aligned with the gaps 98 in the combs 90 and 110, the robot 40 movesthe hand 42 downwardly. As this occurs, the lower edges of the wafers 44come to rest in the gaps 98 in the combs, guided by the surfaces on theteeth 92 and 112. Simultaneously, the downward movement of the hand 42moves the drive stems 178 outwardly, as the drive stems 178 move fromthe inner section 57 of the drive opening 54 in the hand 42, to theouter section 55 of the drive opening.

As this occurs, the lock bars 170 pivot down and away from each other,as shown in FIGS. 19-21. The lower edge 182 of the cam bar 172 movesdownwardly along each cam surface on the upper edge of the cam arm 136.With continued downward movement of the hand 42, the lock bar 170 andretainer 130 move from the position shown in FIG. 19, to the positionsshown in FIG. 20, and ultimately to the positions shown in FIG. 21. (Themovement of the right lock bar 188 and right retainer 160 is equal andopposite (mirror image) of the movement of the left lock bar 170 andleft retainer 130, shown in FIGS. 19-21.) As a result, the contact bar138 moves downwardly in an arc, about the pivot axis of the retainer130, and contacts an upper peripheral edge of the wafers 44, urging thewafers downwardly into secure engagement with the combs. The O-ring 106in the combs provides a resilient stop for the edges of the wafers. Asshown in FIGS. 19 and 20, the contact bar 138 on the retainer 130 ispositioned so that it approaches the wafers 44 virtuallyperpendicularly, so that the contact bar 138 contacts the wafer edgeswith little or no sliding contact. This reduces or avoids creating looseparticles, which can contaminate the wafers.

The movement of the hand 42, as driven by the robot 40 is sufficient toovercome the spring force tending to hold the lock bar and retainer inthe up or open position. However, after the lock bar and retainer aremoved, via the hand 42, into the position shown in FIG. 21, the lockdownassembly 70 will remain in the position shown in FIG. 21, even after thehand 42 is removed, due to the cam bar 182 now being in direct alignmentwith the contact bar 138. Consequently, the spring force acting on theretainer cannot move the retainer away from the wafers 44. Thecentrifugal force on the counterweight 196 also acts to keep the lockbars in the locked down position, in addition to the springs 192 and194.

The first and second curved surfaces 148 and 150 on the top of the camarm 136, together with the configuration of the drive openings 54, causethe wafers to first come to rest in the combs 90 and 110, before thecontact bar 138 begins to exert downward force on the wafers.Consequently, the wafers 44 are first lowered into the combs 90 and 110via their own weight, and then are subsequently forced slightly furtherinto the combs via the lockdown assembly 70. With the wafers securedwithin the rotor 30, clocking motion of the wafers, during accelerationand deceleration and/or vibration of the rotor, during processing, isreduced or eliminated. Consequently, particle generation and resultingcontamination of the wafers, is reduced. As shown in FIGS. 22 and 23,the lockdown assembly 70 holds the wafers 44 within the rotor 60.

Unlike earlier designs, such as in U.S. Pat. No. 5,784,797, the rotor 60contacts the edges of the wafers only with resilient elastomermaterials, i.e., the O-ring strip 106 and the contact bar cover 140.This reduces generation of particle contaminants. In addition, as thewafers are clamped in place, they can be centered within the rotor,rather than being offset, as no centrifugal force is needed to hold themin place. This avoids the forces and associated wear and particlegeneration associated with the eccentric spinning of the earlierdesigns. Clocking of wafers, at start up, and while spinning at highspeed, is reduced or avoided, as rotor out-of-balance conditions areavoided and centrifugal force is not needed to hold the wafers in place.Regardless of whether the wafers are centrally or eccentricallypositioned in the rotor, the springs, lock bars, and retainers,positively clamp the wafers in place, without relying on centrifugalforce, thereby reducing or eliminating unwanted wafer clocking ormovement.

Thus, a novel machine and rotor has been shown and described. Variouschanges can of course be made without departing from the spirit andscope of the invention. The invention, therefor, should not be limited,except by the following claims, and their equivalents.

What is claimed is:
 1. A machine for processing flat media, comprising:a first section for receiving flat media; a second section having atleast one process chamber for processing the flat media; a robot movablebetween the first and second sections; a rotor rotatably mounted in theat least one process chamber, the rotor comprising a front ring, a lockbar pivotably attached to the front ring, and having a drive stemengageable by the robot, and a retainer pivotably attached to the frontring, and biased into engagement with the lock bar.
 2. A machine forprocessing flat media, comprising: a first section for receiving flatmedia; a second section having at least one process chamber forprocessing the flat media; a robot movable between the first and secondsections: a rotor rotatably mounted in the at least one process chamber,the rotor comprising a front ring, a back plate, a pair of baseconnecting bars connecting the front ring and the back plate, a pair ofbase combs on the base connecting bars, a pair of side connecting barsconnecting the front ring and back plate, a pair of side combs on theside connecting bars; and a lock down assembly on the rotor, thelockdown assembly comprising: a left lock bar and a right lock barpivotably attached to the front ring and to the back plate, with theleft lock bar having a drive stem linked to a left cam bar and the rightlock bar having a drive stem linked to a right cam bar; a left retainerand a right retainer pivotably attached to the front ring and to theback plate, with the left retainer and the right retainer having atleast one cam arm biased into contact with the left cam bar and theright cam bar, respectively; the left retainer and the right retainerremoveable, via engagement and movement of the drive stems, from an openposition where articles can be loaded and unloaded into and out of therotor, to a closed position where articles within the rotor are securedinto place between the retainers and the combs.
 3. A machine forprocessing flat media, comprising: a first section for receiving flatmedia; a second section having at least one process chamber forprocessing the flat media; a robot movable between the first and secondsections; a rotor rotatably mounted in the at least one process chamberand having a front ring; a lock bar pivotably attached to the frontring, the lock bar having a drive stem engageable by a loader/unloader;a retainer pivotably attached to the front ring, and biased intoengagement with the lock bar; and at least one cam arm on the retainer,with the cam arm having a cam surface including a first curved surfaceand a second curved surface adjoining the first curved surface.
 4. Themachine of claim 3 wherein the cam surface is configured so that thearticles come to rest on the combs before the contact bar contacts thearticles.
 5. A machine for processing flat media, comprising: a firstsection for receiving flat media; a second section having at least oneprocess chamber for processing the flat media; a robot movable betweenthe first and second sections; a rotor rotatably mounted in the at leastone process chamber, the rotor comprising: combs for supporting the flatmedia; a contact bar having a cam surface with first and second curvedsurfaces, the contact bar engageable at least indirectly by the robot,and moveable from a first position, where flat media can be placed intoor removed from the rotor, to a second position, where the contact barengages the flat media to secure it into place against the combs; and alock bar engaged against the cam surface.
 6. A machine for processingflat media, comprising: a first section for receiving flat media; asecond section having at least one process chamber for processing theflat media; a rotor in the at least one process chamber, the rotorcomprising lock down means for securing flat media into place within therotor, the lock down means comprising a lock down assembly including: aleft lock bar having a drive stem linked to a left cam bar; a right lockbar having a drive stem linked to a right cam bar; a left retainer and aright retainer, with the left retainer and the right retainer having atleast one cam arm biased into contact with the left cam bar and theright cam bar, respectively; the left retainer and the right retainermoveable, via engagement and movement of the drive stems, from an openposition, where, articles can be loaded and unloaded into and out of therotor, to a closed position where articles within the rotor are securedinto place between the retainers and the combs; and transport means formoving flat media into and out of the rotor.
 7. A machine for processingflat media, comprising: a first section for receiving flat media; asecond section having at least one process chamber for processing theflat media; a robot movable between the first and second sections; arotor rotatably mounted in the at least one process chamber, the rotorcomprising: a contact bar moveable from a first position, where flatmedia can be placed into or removed from the rotor, to a secondposition, where the contact bar engages the flat media to secure it intoplace within the rotor; and a lock bar engaged against a cam surface onthe contact bar for urging the contact bar from the first position tothe second position.
 8. The machine of claim 7 wherein the contact barcontacts the flat media perpendicularly and without sliding movementbetween the contact bar and the flat media.
 9. The machine of claim 7further comprising combs on the rotor, the combs having a plurality ofteeth for receiving the flat media.
 10. The machine of claim 9 whereinthe combs comprise at least one base comb and at least one side comb forsecuring the flat media within the rotor.
 11. The machine of claim 10wherein at least one of the teeth of the base comb is formedsubstantially in the shape of a four-sided pyramid having asubstantially rectangular surface at a top end of the tooth.
 12. Themachine of claim 10 wherein at least one of the teeth of the side combhas rounded sides terminating at a flat surface at a top end of thetooth.
 13. The machine of claim 9 wherein at least one comb includes arod comprised of an elastomeric material attached alongside the teeth ofthe comb substantially for an entire length of the comb, the rod adaptedto contact and support edges of the flat media to secure the flat mediawithin the rotor.
 14. The machine of claim 7 wherein the contact barincludes a cover comprised of an elastomeric material.
 15. The machineof claim 7 wherein the cam surface comprises a first curved surfacetransitioning into a second curved surface.
 16. The machine of claim 7wherein the lock bar is engageable by the robot for urging the contactbar from the first position to the second position.
 17. A machine forprocessing flat media, comprising: a first section for receiving flatmedia; a second section having at least one process chamber forprocessing the flat media; a robot moveable from the first section tothe second section; a rotor in the at least one process chamber, therotor comprising contact means moveable from a first position, whereflat media can be placed into or removed from the rotor, to a secondposition, where the contact means engages the flat media to secure itinto place within the rotor, and the rotor also comprising a lockingmeans engaged against the contact means for urging the contact meansfrom the first position to the second position, with the locking meansengageable by the robot.
 18. The machine of claim 17 wherein the contactmeans comprises a contact bar engageable at least indirectly by thetransport means.
 19. The machine of claim 17 wherein the locking meanscomprises a lock bar engageable by the transport means for urging thecontact means from the first position to the second position.
 20. Amachine for processing flat media, comprising: a first section forreceiving flat media; a second section having at least one processchamber for processing the flat media; a robot movable between the firstand second sections; a rotor rotatably mounted in the at least oneprocess chamber, the rotor comprising: a contact bar moveable from afirst position, where flat media can be placed into or removed from therotor, to a second position, where the contact bar engages the flatmedia to secure it into place within the rotor; a lock bar engagedagainst the contact bar for urging the contact bar from the firstposition to the second position; and a spring urging the contact barinto engagement with the lock bar.